Conventional hole cutters, also known as hole saws or cup saws, comprise a circular base, a peripheral wall formed on one side of the base and extending axially therefrom, and multiple cutting teeth machined in the outer edge of the peripheral wall. The base, peripheral wall, and cutting teeth can be machined from a piece of steel to form a hole cutter of unitary construction. An example of a hole saw is illustrated in U.S. Pat. No. 5,803,678, which is incorporated by reference herein in its entirety.
Other conventional hole saws are manufactured by forming the saw teeth in an elongated metal band that makes up a blade body, and then welding the metal band in a circular configuration onto a rigid cap plate. In either case, in an effort to increase cutting speed of the saw blade into a material, the width of the blade body has been decreased over time. While decreasing the width of the blade body can increase cutting speed, it can have some negative side effects. For instance, reducing the width of the blade body reduces the amount of material constituting each tooth, thus a given applied force will generate higher stresses in the thinner cross section. This can result in teeth that are weaker and more prone to breaking off from the blade body.
This potential for breaking off teeth can be increased when the teeth are offset from the blade body. The potential for breaking off teeth can also be increased when the teeth have varying tooth tip heights, as the teeth that extend out further from the blade body are likely to receive more force and have a higher moment during a cutting operation. Further, once one tooth breaks from the saw blade, it is more likely for multiple teeth to break off. Accordingly, reducing tooth break off can increase the useful life of a saw blade.